how to change the backround color in a script unity code example

Example 1: camera color unity

using UnityEngine;
using System.Collections;

public class Myclass: MonoBehaviour
{
    public Color Red = Color.red;
    
    public Camera cam;

    void Start()
    {
      
      
    }

    void Update()
    {
      
        cam.backgroundColor = Red;
    }
}

Example 2: camera color unity

using UnityEngine;
using System.Collections;

public class ExampleClass : MonoBehaviour
{
    public Color color1 = Color.red;
    public Color color2 = Color.blue;
    public float duration = 3.0F;

    public Camera cam;

    void Start()
    {
        
    }

    void Update()
    {
        float t = Mathf.PingPong(Time.time, duration) / duration;
        cam.backgroundColor = Color.Lerp(color1, color2, t);
    }
}